Support devices known as curbs are commonly employed to mount air conditioners on an inclined roof of a building. The air conditioner itself is maintained on the level (in a horizontal attitude) to allow proper operation thereof.
It has been long time practice to custom build curbs so that they can be utilized with roofs of a particular degree of inclination. That is, a particular curb is constructed to maintain the air conditioner at a level for a particular degree of incline.
It is known to provide adjustable curbs which may be utilized for a relatively limited range of roof inclinations. Upon installation, the adjustable curb can be adjusted to ensure that the air conditioner is on the level regardless to the degree or pitch or inclination of the roof to which it is attached.
A representative adjustable curb apparatus for mounting an air conditioner is shown in U.S. Pat. No. 5,454,538 wherein a pivotal interconnection is provided between two support members, the members being secured together by mechanical fasteners to prevent relative movement thereof when the desired relative positioning of the support members is attained.
It is also known to provide modular adjustable curbs which are not pivotally interconnected. An example is the R30-Series MAC curb made available by Modular Metal Fabricators Inc. In this arrangement a base formed from a single layer of galvanized steel sheet is attached to the roof. The base includes four upstanding base sides formed of 18 gauge galvanized steel. An upper module which has wooden elements is nailed directly to wooden elements the base side walls, the installer having positioned the upper module at the desired pitch. Adjustment is quite limited as is the curb height obtainable with such construction. For this reason, different heights of modular adjustable curbs are made available.
Furthermore, a modular adjustable curb arrangement of the prior art type just described is of insufficient strength to resist deformation or failure thereof when supporting an air conditioner in the case of earthquake or application of other comparable forces.